Control and delivery of electric fields via an electrode array

Abstract

A method of controlling electric fields created by a plurality of electrodes. The method includes repetitively applying multiple sets of voltages to at least some of a plurality of electrodes over a treatment period to achieve and maintain a target temperature, the at least some of the electrodes being treatment electrodes. The sets of voltages may be in patterns such that a unique current pattern between electrodes is created for each set of voltages, resulting in temperature averaging. The voltage at each electrode may be determined based on a temperature of an adjacent electrode. The voltage at each electrode may also or alternatively be determined based on an estimated voltage at the electrode.

1 . A method of controlling electric fields created by a plurality of electrodes, comprising:
 repetitively applying multiple sets of voltages to at least some of a plurality of electrodes over a treatment period so as to heat a target tissue to a selected temperature or temperature range, the at least some of the electrodes being treatment electrodes, and the multiple sets of voltages including:   a first set of voltages that creates an electric potential difference between at least some adjacent pairs of the treatment electrodes; and   a second set of voltages that creates an electric potential difference between at least some adjacent pairs of the treatment electrodes for which an electric potential difference was not created while applying the first set of voltages,
 wherein the multiple sets of voltages in combination create an electric potential difference between each adjacent pair of treatment electrodes. 
   
     
     
         2 . The method of  claim 1 , wherein applying the second set of voltages removes an electric potential difference between at least one of the adjacent pairs of treatment electrodes that was created while applying the first set of voltages. 
     
     
         3 . The method of  claim 1 , wherein applying the first set of voltages creates an electric potential difference between a first one of the treatment electrodes and one or more first adjacent treatment electrodes, and applying the second set of voltages creates an electric potential difference between the first one of the treatment electrodes and one or more second adjacent treatment electrodes different than the first adjacent treatment electrodes. 
     
     
         4 . The method of  claim 1 , further comprising applying one or more additional sets of voltages to the treatment electrodes so that, together with application of the first set of voltages and the second set of voltages, a current flow between each adjacent pair of treatment electrodes is approximately the same. 
     
     
         5 . The method of  claim 1 , wherein creating an electric potential difference includes one or more of:
 providing an electrical voltage having a first polarity to a first electrode of a pair of treatment electrodes and an electrical voltage having a second polarity different than the first polarity to a second electrode of the pair of treatment electrodes;   providing an electrical voltage having a first phase to a first electrode of a pair of treatment electrodes and an electrical voltage having a second phase different than the first phase to a second electrode of the pair of treatment electrodes; and   providing an electrical voltage having a first amplitude to a first electrode of a pair of treatment electrodes and an electrical voltage having a second amplitude different than the first amplitude to a second electrode of the pair of treatment electrodes.   
     
     
         6 . The method of  claim 1 , further comprising:
 applying a feedback control loop controlling the electrical voltage provided to the treatment electrodes, wherein applying a feedback control loop includes, for each treatment electrode:   adjusting a voltage applied to the electrode based at least in part on one or more of:   a temperature difference for the electrode based on a temperature of an adjacent electrode; and   an estimate of a voltage at the electrode provided by one or more other electrodes.   
     
     
         7 . The method of  claim 6 , further comprising, for each treatment electrode:
 reading an electrode temperature of the treatment electrode;   reading an electrode temperature of one or more electrodes that are located adjacent to the treatment electrode; and   if a temperature of one of the adjacent electrodes is higher than the temperature of the treatment electrode, then adjusting the voltage applied to the treatment electrode based on the higher temperature.   
     
     
         8 . The method of  claim 6 , further comprising, for each treatment electrode:
 identifying voltages of adjacent electrodes;   adjusting the identified voltages based on a distance of the adjacent electrodes from the treatment electrode;   determining the average of the adjusted voltages; and   adjusting the voltage applied to the treatment electrode based on the average of the adjusted voltages.   
     
     
         9 . A system for selectively generating electric fields, comprising:
 a plurality of electrodes; and
 a control unit including a storage medium and a computer processor, the storage medium having executable instructions stored thereon, wherein the computer processor is operable to execute the instructions so as to cause the control unit to perform operations including: 
   switching between unique electrode patterns so as to heat a target tissue to a selected temperature or temperature range, where each unique electrode pattern includes providing an electrical voltage to at least some of the electrodes, the at least some electrodes being treatment electrodes, and the electrical voltage being provided so as to generate a current flow between adjacent pairs of the treatment electrodes; and   applying a feedback control loop controlling the electrical voltage provided to the treatment electrodes based at least in part on one or more of:
 a temperature difference for a treatment electrode based on a temperature of an adjacent treatment electrode; and 
 an estimate of a voltage at a treatment electrode provided by one or more other treatment electrodes. 
   
     
     
         10 . The system of  claim 9 , further comprising:
 a user interface device coupled to the control unit, the user interface operable to:   
       display a graphical representation of a plurality of electrodes, the graphical representation including one or more of a voltage of each electrode, a current of each electrode, and a temperature of each electrode; and 
       receive a user input selecting at least some of the plurality of electrodes to be electrically connected to a power source;
 wherein the control unit is operable to apply a voltage to the selected electrodes. 
 
     
     
         11 . The system of  claim 10 , wherein the graphical representation of the plurality of electrodes includes a plurality of electrode elements corresponding to the plurality of electrodes and arranged to correspond to a physical layout of the plurality of electrodes. 
     
     
         12 . The system of  claim 9 , further comprising:
 a plurality of flexible conductive wires corresponding to the plurality of electrodes, a first end of each wire being mechanically coupled to an end of an electrode; and   a housing for selectively receiving the plurality of electrodes, the housing including:   a side surface having apertures for receiving the plurality of electrodes; and   an interface mechanically coupled to a second end of the plurality of wires for providing an electrical coupling to the plurality of electrodes.   
     
     
         13 . The system of  claim 12 , wherein the apertures are sized to receive the electrodes and are spaced apart from one another so as to electrically insulate the plurality of elongated electrodes from one another when the housing receives the electrodes. 
     
     
         14 . The system of  claim 9 , further comprising:
 a first electrode template having a plurality of apertures for receiving the plurality of electrodes;   a second electrode template having a plurality of apertures for receiving the plurality of electrodes; and   an adjustable template securing apparatus mechanically couplable to the first electrode template and the second electrode template, the adjustable template securing apparatus including:   a first template mount for supporting the first electrode template;   a second template mount for supporting the second electrode template; and   a distance adjustment element mechanically couplable to the first template mount and the second template mount for adjusting a distance between the first electrode template and the second electrode template,
 wherein at least one of the first template mount and the second template mount is removable from the electrode template it supports. 
   
     
     
         15 . The system of  claim 14 , wherein the electrode templates each include at least one securing element extending from a surface of the template, and the template mounts each include at least one cutout for receiving the at least one securing element of a corresponding template. 
     
     
         16 . The system of  claim 14 , wherein the second template mount includes at least one aperture for receiving the distance adjustment element. 
     
     
         17 . A control unit for controlling electric fields created by a plurality of electrodes, the control unit including a storage medium and a computer processor, the storage medium having executable instructions stored thereon, wherein the computer processor is operable to execute the instructions so as to cause the control unit to perform operations including:
 applying a feedback control loop controlling an electrical voltage provided to at least some of a plurality of electrodes so as to heat a target tissue to a selected temperature or temperature range, the at least some electrodes being treatment electrodes, wherein applying a feedback control loop includes, for each treatment electrode:   adjusting a voltage applied to the electrode based at least in part on one or more of:   a temperature difference for the electrode based on a temperature of an adjacent electrode; and   an estimate of a voltage at the electrode provided by one or more other electrodes.   
     
     
         18 . The control unit of  claim 17 , wherein adjusting a voltage includes:
 reading an electrode temperature of the electrode;   reading an electrode temperature of one or more treatment electrodes that are located adjacent to the electrode; and   if a temperature of one of the adjacent electrodes is higher than the temperature of the electrode, then adjusting the voltage applied to the electrode based on the higher temperature.   
     
     
         19 . The control unit of  claim 17 , wherein adjusting a voltage includes:
 identifying voltages of adjacent electrodes;   adjusting the identified voltages based on a distance of the adjacent electrodes from the electrode;   determining the average of the adjusted voltages; and   adjusting the voltage applied to the electrode based on the average of the adjusted voltages.   
     
     
         20 . The control unit of  claim 17 , wherein the computer processor is operable to execute the instructions so as to cause the control unit to perform operations further including:
 repetitively applying multiple sets of voltages to the treatment electrodes, the multiple sets of voltages including:   a first set of voltages that creates an electric potential difference between at least some adjacent pairs of the treatment electrodes; and   a second set of voltages that creates an electric potential difference between at least some adjacent pairs of the treatment electrodes for which an electric potential difference was not created while applying the first set of voltages,
 wherein the multiple sets of voltages in combination create an electric potential difference between each adjacent pair of treatment electrodes.